JP2001010031A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having good color developing of a recording image while incorporating a cloth like peculiar feeling and good preservability of a durable and recording image of a sheet in the case of using outdoor. SOLUTION: An ink receptive layer is provided on one surface of a nonwoven fabric containing a fiber having a fiber size of 0.3 to 20 μm and a value obtained by dividing a length of the fiber by the fiber size of 800 to 10,000 as main body fiber. An ink receptive layer is provided on one surface of a nonwoven fabric blended with 1 to 50 pts. or less of heat fusion bonded fibers to 100 pts. of the main body fiber having a fiber size of 0.3 to 20 μm and a value obtained by dividing a fiber length by a fiber size of 800 to 10,000. Particularly, the layer contains a synthetic noncrystalline silica having a mean particle size of 2 to 10 μm as a white pigment, thereby further improving the prservability of a recorded image in the case of allowing to leave to stand for outdoor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more particularly to a recording sheet having a unique texture, good color development of a recorded image, and good storage stability of the recorded image when used outdoors. It relates to an ink jet recording sheet.

[0002]

2. Description of the Related Art Ink-jet recording is a method in which minute droplets of ink are made to fly and adhere to a recording sheet such as paper by various operating principles to record images and characters. It has features such as easy multi-coloring, great flexibility in recording patterns, and no need for development-fixing, and is rapidly spreading in various applications as a recording device for various figures including Chinese characters and color images. Further, it is possible to obtain an image formed by the multi-color ink jet recording method which is comparable to multi-color printing by the plate making method. In addition, in applications requiring a small number of copies, it is being widely applied to the field of full-color image recording because of its low cost.

As a recording sheet used in the ink jet recording system, there is a high quality paper or a coated paper used for ordinary printing or writing, or a sheet provided with an ink receiving layer to improve the ink jet recording suitability.
In recent years, as the performance of an ink jet printing apparatus has been improved and the use thereof has been expanded, such as an increase in the speed, definition, and full color of the apparatus, more advanced characteristics have been required for a recording sheet.

[0004] That is, the recording sheet has a high density of print dots, a bright and vivid color tone, quick absorption of ink, no ink bleeding or bleeding even when the print dots overlap, High image reproducibility is required such that the diffusion in the horizontal direction is not unnecessarily large and the periphery is smooth and not blurred.

On the other hand, in the fields of design, events, advertisements, etc., a color image which uses a durable or water-resistant support and is characterized by the texture of the support itself is used for posters and signs. Records are widespread. Under such circumstances, various types of ink jet recording fabrics using a fabric such as a woven fabric, a knitted fabric, or a nonwoven fabric as a support have been proposed (JP-A-2-09677, JP-A-2-219679, JP-A-6-219679). 128854). However, since such a fabric is more porous than paper or film, even if an ink receiving layer is provided in order to improve the suitability for ink jet recording, the coating amount of the ink receiving layer is increased, which is not only uneconomical. When the amount of coating is increased, the sheet becomes hard and the texture peculiar to the fabric is lost. Further, a large number of voids are formed on the surface of the coating layer of the ink receiving layer, resulting in a problem that the print density is low and the color tone is unclear. A method of increasing the viscosity of the coating liquid for the ink receiving layer (JP-A-62-53493) has also been proposed, but the effect is insufficient.

[0006] Further, the use of ink-jet recorded sheets for outdoor posters, signboards, and the like is increasing. In this case, naturally, the ink jet recording sheet is exposed to sunlight, wind and rain. Due to these effects, there has been a problem that the ink jet recording sheet becomes unsightly in appearance, such as being damaged and causing paper breakage, and a recorded image being discolored. In particular, when the coating layer strength of the ink receiving layer is low, the ink jet recording sheet is rubbed in the wind, whereby the ink receiving layer is peeled off from the support with the printed image, and the image density is reduced.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording sheet having a unique cloth-like texture, exhibiting good ink jet recording suitability, and having good storage stability of recorded images when used outdoors. Is provided.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have reached the following invention.

In an ink jet recording sheet having an ink receiving layer provided on one surface of a support, the support has a fiber diameter of 0.3 μm to 20 μm, and the value obtained by dividing the fiber length by the fiber diameter is 800 μm. An invention of an ink jet recording sheet, characterized in that it is a non-woven fabric mainly comprising fibers of 10,000 or less.

In an ink jet recording sheet provided with an ink receiving layer on one surface of a support, the support has a fiber diameter of 0.3 μm to 20 μm and a value obtained by dividing the fiber length by the fiber diameter. An ink jet recording sheet according to the invention, wherein the non-woven fabric is a non-woven fabric containing 800 to 10,000 fibers as main fibers and 1 to 50 parts of heat-fused fibers with respect to 100 parts of the main fibers.

The ink receiving layer has a mean particle size of 2 as a white pigment.
An inkjet recording sheet according to the present invention is characterized by containing synthetic amorphous silica having a size of not less than μm and not more than 10 μm.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ink jet recording sheet according to the present invention will be described in detail. The inkjet recording sheet of the first aspect of the present invention is a nonwoven fabric in which a support has a fiber diameter of 0.3 μm or more and 20 μm or less, and a fiber obtained by dividing a fiber length by a fiber diameter is 800 or more and 10,000 or less as a main fiber. It is characterized by the following. In the present invention, the main fiber means that the fibers in the above range occupy 70% or more in terms of the number of fibers. Preferably it is 90% or more. An ink jet recording sheet provided with an ink receiving layer on a nonwoven fabric prepared using the above fibers has a good texture of the sheet, excellent color development of a recorded image, a strong strength of the sheet, and is sufficient for outdoor use. It turned out to be tolerable.

The fiber diameter of the main fibers constituting the nonwoven fabric used in the present invention must be in the range of 0.3 μm to 20 μm. Preferably it is 1 μm or more and 15 μm or less, more preferably 2 μm or more and 10 μm or less. The fiber diameter here refers to the diameter of the fiber assuming that the shape of the fiber cross section is a perfect circle. When the cross section of the fiber is not a perfect circle, the cross sectional area is calculated from a photograph of the cross section of the fiber, and the calculated diameter is defined as the diameter of the perfect circle corresponding to the sectional area. When the fiber diameter is smaller than 0.3 μm, the sheet becomes dense, and the ink absorbency at the time of ink jet printing is reduced, and bleeding occurs.
Further, the water resistance of the printed portion also decreases. Also, when a non-woven fabric is formed using fibers having a fiber diameter exceeding 20 μm,
When an ink receiving layer is provided on one side of the nonwoven fabric, the ink receiving layer penetrates into the inside of the nonwoven fabric, and not only the texture unique to the nonwoven fabric is lost due to excessive coating amount of the ink receiving layer, but also the coating amount is reduced. However, the density of the printed image is undesirably reduced. Further, when the fiber diameter exceeds 20 μm, the fiber streaks in the printing portion become conspicuous, which is not preferable.

The value obtained by dividing the fiber length of the main fiber constituting the nonwoven fabric used in the present invention by the fiber diameter is 800 to 1,000.
It must be in the range of 0 or less. Preferably 500 or more and 10000 or less, more preferably 1000 or more and 500
0 or less. If the value obtained by dividing the fiber length by the fiber diameter is smaller than 800, the entanglement between the fibers becomes insufficient and the strength of the produced nonwoven fabric is weak, and the ink jet recording sheet provided with the ink receiving layer on the nonwoven fabric is exposed to outdoor weather. If this occurs, the paper will break and will not withstand use. If the value obtained by dividing the fiber length by the fiber diameter exceeds 10,000, handling of the fibers becomes complicated. In other words, it takes a long time to disintegrate the fibers, or the disintegration is insufficient, so that lumps in which the fibers are entangled easily occur. When an ink receiving layer is provided on such a lint-free nonwoven fabric to form an ink jet recording sheet, the appearance of the sheet deteriorates, which is not preferable. Further, when continuous filaments having a fiber diameter in the above range are used, the strength of the sheet is weak, possibly due to insufficient entanglement of the fibers, which is not suitable for outdoor use.

The fibers forming the nonwoven fabric used in the support of the present invention include polyester fibers such as polyethylene terephthalate, polybutylene terephthalate or homopolymers and copolymers of modified polymers of these polymers, polypropylene, polyethylene, polystyrene, and the like.
Or polyolefin fibers such as homopolymers and copolymers such as modified polymers of these polymers; polyacrylonitrile fibers such as acrylic fibers and modacrylic fibers; polyamide fibers such as nylon 6 and nylon 66; and polyvinyl alcohol fibers. And synthetic fibers such as urethane fibers; regenerated cellulose fibers such as rayon; and regenerated fibers such as fibers spun from collagen, alginic acid, chitin, and the like; semi-synthetic fibers such as acetate fibers. Fiber and the like. Among these, polyester-based fibers, polyacrylonitrile-based fibers, and polyamide-based fibers are preferable in terms of the feel of the sheet and the coloring of images when an ink-receiving layer is provided on one surface of the nonwoven fabric to form an ink jet recording sheet. used. Various fibers such as natural fibers such as cellulosic fibers such as hemp, cotton, and pulp, and protein fibers such as wool and silk; inorganic fibers such as metal fibers, glass fibers, and carbon fibers; May be blended.

The nonwoven fabric used in the support of the present invention is roughly classified into a wet nonwoven fabric, a dry nonwoven fabric by a stitch bond method, a spun bond method, a melt blow method, a thermal bond method, etc. There is lace nonwoven fabric. From the viewpoint of sheet strength and texture, a spunlaced nonwoven fabric using a wet nonwoven fabric or a dry nonwoven fabric is preferably used.

In order to produce the ink jet recording sheet of the present invention, it is necessary to provide an ink receiving layer on one surface of the nonwoven fabric of the present invention. The means include various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters, short dwell coaters, comma coaters, die coaters, reverse roll coaters, kiss coaters, curtain coaters, extrusion coaters, gate roll coaters, A coating device such as a gravure coater or a microgravure coater can be used.

As a pretreatment for the nonwoven fabric, for example, it is possible to use a known technique such as performing a corona treatment, providing an undercoat layer or a backcoat layer, or performing a calendar treatment without any problem. .

In the ink receiving layer used in the present invention,
One or more known white pigments can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate,
White inorganic pigments such as magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide, styrene-based plastic pigment, and acrylic Organic pigments such as plastic pigment, polyethylene, microcapsules, urea resin, and melamine resin. Among the above, as the white pigment contained as the main component in the ink receiving layer, a porous inorganic pigment is preferable, and porous synthetic amorphous silica, porous magnesium carbonate, porous alumina, and the like, and particularly, Large volume porous synthetic amorphous silica is preferred.

The average particle size of the synthetic amorphous silica is 2
It is preferable that it is not less than μm and not more than 10 μm. On the nonwoven fabric of the present invention, an ink jet recording sheet provided with an ink receiving layer containing the synthetic amorphous silica having the above-mentioned particle size as a white pigment, after printing an image, when left outdoors, fading of the recorded image occurs. It was found to be difficult to exhibit good image storability. Probably, when the particle size of the synthetic amorphous silica is defined in the above range, the adhesive strength between the nonwoven fabric of the present invention and the ink receiving layer, and the coating layer strength of the ink receiving layer itself become strong, so that outdoor wind and rain, especially It is considered that the coating layer of the ink receiving layer hardly peels off when exposed to the wind, and that the image storability is improved. If the particle size of the synthetic amorphous silica is smaller than 2 μm, bleeding is likely to occur on a printed image, and the water resistance is also likely to be poor. When the particle size exceeds 10 μm, the adhesive strength between the nonwoven fabric of the present invention and the ink receiving layer, and the coating strength of the ink receiving layer itself become weak, and when exposed to wind and rain, the recorded image density due to coating layer peeling is reduced. The drop is easy to occur.

The ink receiving layer of the present invention may contain a cationic dye fixing agent. Examples of the cationic dye fixing agent include secondary amines, tertiary amines, and quaternary ammonium salts. These cationic dye fixing agents include a water-soluble direct dye, which is a dye component of an aqueous ink in an ink receiving component, and a water-soluble dye. To form an insoluble salt with the sulfonic acid group, carboxyl group, amino group, etc. in the acidic acid dye, the dye is captured in the ink receiving layer, and water is dropped or absorbed by improving color and forming an insoluble salt. To prevent the ink from flowing or bleeding, thereby improving the water resistance.

The adhesive used in the ink receiving layer of the present invention includes, for example, polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soybean protein. Conjugated diene copolymer latex such as styrene-butadiene copolymer and methyl methacrylate-butadiene copolymer; polymer or copolymer of acrylic acid ester and methacrylic acid ester; acrylic acid and methacrylic acid Acrylic polymer latex such as acid polymer or copolymer; Vinyl polymer latex such as ethylene-vinyl acetate copolymer; or functional group based on functional group-containing monomer such as carboxyl group of these various polymers Modified polymer latex Aqueous adhesives such as thermosetting synthetic resins such as melamine resin and urea resin; Synthetic resin adhesives such as polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and alkyd resin Agents,
Used in one or more types.

Further, other additives include a pigment dispersant, a thickener, a fluidity improver, a pH adjuster, an antifoaming agent, a foam inhibitor, a release agent, a foaming agent, a penetrant, a coloring dye, and a coloring agent. Pigments, fluorescent brighteners, ultraviolet absorbers, antioxidants, antiseptics, anti-binders, water-proofing agents, wet-strength agents, dry-strength agents, and the like can be appropriately compounded in the ink-receiving layer. .

In the ink jet recording sheet of the present invention, the coating amount of the ink receiving layer is not particularly limited, but is preferably 3 g / m ² or more and 50 g / m ² or less, more preferably 5 g / m ² or more. 35 g / m ² or less. If the coating amount is less than 3 g / m ² , the ink absorbing ability is reduced and bleeding is liable to occur, and the fiber streaks in the printing portion become conspicuous. When the coating amount exceeds 50 g / m ² ,
Not only is the printing quality saturated and uneconomical, but the powder in the ink receiving layer becomes noticeable, and the curl of the product tends to be severe.

After the ink receiving layer is provided on the nonwoven fabric, flattening may be performed using a calender such as a machine calender, a TG calender, a super calender, and a soft calender. In addition, on the opposite side of the support from the ink receiving layer, it is possible to perform a conductive treatment or to use a known technique such as providing a back coat layer in order to improve printer paper passing property without any problem. it can. Further, an ink receiving layer may be further provided on the surface of the support opposite to the ink receiving layer to form an ink jet recording sheet capable of printing on both sides.

In the ink jet recording sheet according to the second aspect of the present invention, the support has a fiber diameter of 0.3 μm to 20 μm, and a value obtained by dividing the fiber length by the fiber diameter is 800 to 100.
It is a nonwoven fabric containing 1 to 50 parts of heat-fused fibers with respect to 100 parts of main fibers of 100 or less. In the present invention, the heat-fused fiber refers to a fiber in which the fiber is melted by heating in a drying step in manufacturing a nonwoven fabric and loses its original fiber form. In the present invention, the heat-fused fibers are not included in the category of fibers because the heat-fused fibers lose their original fiber form when formed into a nonwoven fabric. An ink jet recording sheet provided with an ink receiving layer on one surface of a nonwoven fabric containing heat-fused fibers as described above has a unique cloth-like texture,
Not only was the sheet strong and usable outdoors, but also unexpectedly, it was found that the surface of the ink receiving layer was smooth and the color of the recorded image was further improved. By blending the heat-fusible fibers, these heat-fusible fibers are melted and formed into a film in a drying step when a nonwoven fabric is produced. Probably, the nonwoven fabric thus obtained has a smooth surface and suppresses the permeability of the coating liquid for the ink receiving layer, so that the smoothness of the ink receiving layer is improved.

The blending portion of the heat-fused fiber has a fiber diameter of 0.3 μm
Not less than 20 μm, and the value obtained by dividing the fiber length by the fiber diameter is preferably 1 part or more and 50 parts or less, more preferably 5 parts or more and 35 parts or less with respect to 100 parts of the main fiber of 800 or more and 10,000 or less. It is as follows. If the amount of the heat-fused fiber is less than 1 part, the effect is less likely to be obtained. If the amount is more than 50 parts, the produced nonwoven fabric becomes hard and loses a unique texture like cloth.

Examples of the heat-fusible fibers include low-melting type polyethylene terephthalate-based fibers, polyacrylonitrile-based fibers, polyamide-based fibers, polyethylene-based fibers, polypropylene-based fibers, and the like. A core-sheath fiber having a melting point fiber as a core component and a side-by-side fiber in which one of the components is a low melting point fiber are exemplified.

The melting point of the heat-fused fiber is, for example, 50 ° C. or higher and 2
When the melting point is too low, the heat-fused fiber is likely to melt and handling becomes complicated if the melting point is too low. Becomes insufficient, and it is difficult to obtain the expected effect. From such a background, the melting point of the heat-fusible fiber is preferably from 80 ° C to 170 ° C, more preferably 10 ° C to 170 ° C.
0 ° C or more and 150 ° C or less.

The fiber diameter and fiber length of the heat-fused fibers are selected within a range in which a nonwoven fabric can be produced together with the main fibers. The diameter of the heat-fused fiber is 1 μm or more and 5
0 μm or less, the value obtained by dividing the fiber length by the fiber diameter is 500 or more and 1
Those having 5,000 or less are preferably used.

The ink jet recording sheet according to the first aspect of the present invention supports a nonwoven fabric mainly composed of fibers having a fiber diameter of 0.3 μm to 20 μm and a fiber length divided by a fiber diameter of 800 to 10,000. By using it as a body, it is possible to obtain an ink jet recording sheet having a unique cloth-like texture, good color development of a recorded image, strong sheet strength, and endurable for outdoor use. The ink-jet recording sheet of the second aspect of the present invention has, as a support, a fiber having a fiber diameter of 0.3 μm or more and 20 μm or less, and a value obtained by dividing the fiber length by the fiber diameter of 100 parts or more of the main fibers having a fiber length of 800 or more and 10,000 or less. On the other hand, by using a nonwoven fabric in which 1 to 50 parts of heat-fused fibers are blended, in addition to the above-mentioned properties, an ink jet recording sheet having a smoother surface of the ink receiving layer and more favorable coloring of the recorded image is obtained. It becomes possible. Further, in the above two inventions, by containing a synthetic amorphous silica having an average particle diameter of 2 μm or more and 10 μm or less as a white pigment in the ink receiving layer, in addition to the above characteristics, the discoloration of a recorded image when left outdoors is reduced. It is possible to provide an ink jet recording sheet that hardly occurs and exhibits good image storability.

[0032]

EXAMPLES The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples. In Examples and Comparative Examples, “parts” and “%”
Unless indicated otherwise, parts by weight and% by weight are indicated.

Preparation of Coating Solution for Ink Receiving Layer 100 parts of synthetic amorphous silica (Nipsil E150J: manufactured by Nippon Silica Industry, average particle size 4.0 μm), 30 parts of polyvinyl alcohol (PVA117: manufactured by Kuraray), cationic dye fixing agent (Sumireze resin 1001: manufactured by Sumitomo Chemical Co., Ltd.) was used, and the mixture was prepared.
3%.

Example 1 The fiber diameter was 3 to 5 μm, and the value obtained by dividing the fiber length by the fiber diameter was 250.
0-3000 polyethylene terephthalate fiber 100
And an aqueous slurry composed of 5 parts of hot water-soluble polyvinyl alcohol fiber, and a basis weight of 50 using a wet papermaking method.
g / m < ² > nonwoven fabric was produced. The hot water-soluble polyvinyl alcohol fiber does not maintain its form as a fiber due to the heat during drying, and is present between the polyethylene terephthalate fibers as a binder. A columnar flow of high-speed water spouted from a number of orifices having a diameter of 100 μmφ was made to collide with the nonwoven fabric once at each of the front and back sides to perform spunlace processing. At the time of spunlace processing, the hot water-soluble polyvinyl alcohol fibers are dissolved in water, so that the nonwoven fabric is composed of fibers having a fiber diameter of 3 to 5 μm.
On one surface of the nonwoven fabric thus obtained, the coating liquid obtained in the preparation of the coating liquid for the ink receiving layer was applied using an air knife coater so that the coating amount after drying was 20 g / m ^2, and the coating was dried. An ink jet recording sheet of the invention was obtained.

Example 2 Example 2 was repeated except that the polyethylene terephthalate fiber used in Example 1 was changed to a polyethylene terephthalate fiber having a fiber diameter of 0.4 to 0.7 μm and a fiber length divided by a fiber diameter of 820 to 1,000. In the same manner as in Example 1, an ink jet recording sheet of the present invention was produced.

Example 3 Example 3 was repeated except that the polyethylene terephthalate fiber used in Example 1 was changed to a polyacrylonitrile fiber having a fiber diameter of 0.4 to 0.7 μm and a fiber length divided by a fiber diameter of 9000 to 9800. In the same manner as in Example 1, an ink jet recording sheet of the present invention was produced.

Example 4 The polyethylene terephthalate fiber used in Example 1 had a fiber diameter of 16 to 19 μm, and the fiber length divided by the fiber diameter was 8
An ink jet recording sheet of the present invention was produced in the same manner as in Example 1 except that the polyethylene terephthalate fibers of 20 to 1,000 were used.

Example 5 The polyethylene terephthalate fiber used in Example 1 had a fiber diameter of 16 to 19 μm, and the fiber length divided by the fiber diameter was 9
An ink jet recording sheet of the present invention was produced in the same manner as in Example 1, except that polyacrylonitrile fibers of 000 to 9800 were used.

Example 6 The fiber diameter was 3 to 5 μm, and the value obtained by dividing the fiber length by the fiber diameter was 250.
0-3000 polyethylene terephthalate fiber 100
Part, 1 part of heat fusion fiber (Melty 3380: manufactured by Unitika,
A water-based slurry having a melting point of 130 ° C.) was prepared, and a nonwoven fabric having a basis weight of 50 g / m ² was prepared by a wet papermaking method. The heat-fused fiber does not maintain its form as a fiber due to heat during drying, and exists as a binder between the polyethylene terephthalate fibers, and the nonwoven fabric has a fiber diameter of 3 to
It will be composed of 5 μm fibers. A columnar flow of high-speed water spouted from a number of orifices having a diameter of 100 μmφ was made to collide with the nonwoven fabric once each on the front and back sides to perform spunlace processing. On one surface of the nonwoven fabric thus obtained, the coating liquid obtained in the preparation of the coating liquid for the ink receiving layer was applied using an air knife coater so that the coating amount after drying was 20 g / m ^2, and the coating was dried. An ink jet recording sheet of the invention was obtained.

Example 7 An ink jet recording sheet of the present invention was produced in the same manner as in Example 6, except that the blending portion of the heat-fusible fiber was changed from 1 part to 20 parts.

Example 8 An ink jet recording sheet of the present invention was produced in the same manner as in Example 6, except that the blending portion of the heat-fusible fiber was changed from 1 part to 48 parts.

Example 9 In place of the synthetic amorphous silica used in the preparation of the coating liquid for the ink receiving layer, 100 parts of Nipsil E220 (manufactured by Nippon Silica Industry Co., Ltd., average particle size 1.5 μm) was used. The liquid was adjusted. An ink jet recording sheet of the present invention was produced in the same manner as in Example 1 except that the thus obtained ink receiving layer coating solution was used.

Example 10 Instead of the synthetic amorphous silica used in the preparation of the coating liquid for the ink receiving layer, Nipsil E200A (manufactured by Nippon Silica Kogyo Co., Ltd.)
The coating liquid for the ink receiving layer was adjusted using 100 parts of an average particle diameter of 2.0 μm. An ink jet recording sheet of the present invention was produced in the same manner as in Example 1 except that the thus obtained ink receiving layer coating solution was used.

Example 11 Instead of the synthetic amorphous silica used in the preparation of the ink receiving layer coating solution, 100 parts of Mizukasil P-363 (manufactured by Mizusawa Chemical Industries, average particle size: 10 μm) was used, and the ink receiving layer was used. The coating liquid was adjusted. An ink jet recording sheet of the present invention was produced in the same manner as in Example 1 except that the thus obtained ink receiving layer coating solution was used.

Example 12 In place of the synthetic amorphous silica used in the preparation of the coating liquid for the ink receiving layer, 100 parts of Mizukasil P-78F (manufactured by Mizusawa Chemical Industries, average particle size: 12 μm) was used to prepare the ink receiving layer. The coating liquid was adjusted. An ink jet recording sheet of the present invention was produced in the same manner as in Example 1 except that the thus obtained ink receiving layer coating solution was used.

Example 13 Instead of the synthetic amorphous silica used in the preparation of the coating liquid for the ink receiving layer, 100 parts of Mizukasil P-78F (manufactured by Mizusawa Chemical Industries, average particle size: 12 μm) was used, and the ink receiving layer was used. The coating liquid was adjusted. An ink jet recording sheet of the present invention was produced in the same manner as in Example 7, except that the thus-obtained ink receiving layer coating liquid was used.

Comparative Example 1 A melt-blown non-woven fabric was prepared using polyethylene terephthalate fiber composed of continuous filaments having a fiber diameter of 3 to 5 μm as a support, and the non-woven fabric was subjected to spunlace processing and an ink-receiving layer in the same manner as in Example 1. Coating was performed to produce an ink jet recording sheet. In this case, the value obtained by dividing the fiber length by the fiber diameter is infinite.

Comparative Example 2 The procedure of Example 1 was repeated except that the polyethylene terephthalate fiber used in Example 1 was changed to a polyethylene terephthalate fiber having a fiber diameter of 0.1 to 0.2 μm and a fiber length divided by a fiber diameter of 2500 to 3000. In the same manner as in Example 1, an ink jet recording sheet was produced.

Comparative Example 3 The polyethylene terephthalate fiber used in Example 1 had a fiber diameter of 21 to 24 μm, and the fiber length divided by the fiber diameter was 2
An ink jet recording sheet was produced in the same manner as in Example 1 except that the polyethylene terephthalate fibers of 500 to 3000 were used.

Comparative Example 4 The polyethylene terephthalate fiber used in Example 1 had a fiber diameter of 2 to 5 μm and the fiber length divided by the fiber diameter was 600.
An ink jet recording sheet was produced in the same manner as in Example 1 except that the polyethylene terephthalate fibers of Nos. To 750 were changed.

Comparative Example 5 The polyethylene terephthalate fiber used in Example 1 had a fiber diameter of 3 to 5 μm and the fiber length divided by the fiber diameter was 110.
An ink jet recording sheet was produced in the same manner as in Example 1 except that the polyethylene terephthalate fibers of No. 00 to 12000 were changed. The ink-jet recording sheet thus obtained had poor texture, and lumps formed by entangled fibers were conspicuous, and the appearance was not very good.

<Test Method> 1) Sheet Flexibility The flexibility of the ink jet recording sheet was determined according to the following criteria. ：: It is flexible and has a unique cloth-like texture. ：: The sheet is slightly stiff, but still has a cloth-like unique feel. ×: The sheet is hard, and the cloth-like unique feel is completely lost. Alternatively, there is a problem with the appearance of the sheet.

2) Print Density The recording sheets prepared in Examples and Comparative Examples were cut to A4 size, and then an ink jet printer using a pigment ink (Design Jet2 manufactured by Hewlett-Packard) was used.
(500 CP), solid printing of 100% for each color of black, cyan, magenta, and yellow was performed. Macbeth RD91
At 9, the density of the printed portion was measured. Larger values indicate higher print density and better printability.

3) Water resistance After the recording sheets prepared in Examples and Comparative Examples were cut to A4 size, an ink jet printer using a pigment ink (Design Jet 2 manufactured by Hewlett-Packard) was used.
(500 CP), solid printing of 100% for each color of black, cyan, magenta, and yellow was performed, and the density of the printed portion was measured by Macbeth RD919. This sheet was immersed in the water in the vat for one day. Leave the sheet removed from the water on a horizontal table with the ink receiving layer facing up.
Air drying was performed. The density of the printed portion after air drying was measured in the same manner using Macbeth RD919. For each color, the residual ratio of print density represented by the following equation was calculated and used as an index of water resistance. The values in the table indicate the average values of the print density residual rates of the respective colors. Larger values indicate better water resistance, and 97
If it is more than%, it was judged that it was a practical level. Print density residual rate (%) = (A / B) × 100 A: Print density after water resistance test B: Print density before water resistance test

4) Outdoor Leaving Test The recording sheets produced in the examples and comparative examples were finished into small rolls having a width of 610 mm, and then outdoor banners were produced. For the purpose of imparting light resistance, an ink jet printer using pigment ink (Due manufactured by Hewlett-Packard)
signJet2500CP). The banner thus produced was allowed to stand outdoors for one month, and the appearance of the sheet and the change in the density of the printed portion were determined according to the following criteria. A) Sheet appearance A: There is no tearing of the sheet and almost no wrinkles are observed. ：: The sheet is not torn, but slightly wrinkled. ×: The sheet is torn or partially missing. Alternatively, many severe wrinkles are generated, and the appearance is unsightly. B) Density change in the printed area A: Little change in density was observed, and the original clear image was maintained. ：: Although the concentration is slightly lowered, there is no practical problem. ×: A large decrease in the density was observed, and there was a problem in practical use.

[0056]

[Table 1]

As is clear from the table, the fiber diameter is 0.3 μm.
Examples 1 to 5 and Examples 9 to 9 using a non-woven fabric having a fiber whose main fiber is a fiber whose fiber length divided by a fiber diameter is 800 to 10000 or less.
No. 12 has a unique cloth-like texture, has good coloration of a recorded image, and has a high sheet strength, and can be used as an inkjet recording sheet that can withstand outdoor use. In particular,
As shown in Examples 1 to 5 and Examples 10 to 11,
The ink receiving layer is a white pigment having an average particle size of 2 μm or more and 10
When synthetic amorphous silica having a particle size of not more than μm is contained, an ink jet recording sheet having good image storability without fading of a recorded image after being left outdoors, in addition to the above characteristics, can be obtained.

The fiber diameter is 0.3 μm or more and 20 μm or less, and the value obtained by dividing the fiber length by the fiber diameter is 800 to 1
In Examples 6 to 8 and Example 13 in which the nonwoven fabric in which 1 to 50 parts of the heat-fusible fiber was blended was used for the support for 100 parts of the main fiber of 0000 or less, the case where the heat-fusible fiber was not blended was used. Furthermore, the color development of the recorded image is improved, and an ink jet recording sheet that can be used outdoors while having a cloth-like texture can be obtained. This is because the surface of the ink receiving layer of the ink jet recording sheet is affected by the fact that the surface of the nonwoven fabric is smoothed or the penetration of the ink receiving layer coating liquid into the nonwoven fabric is suppressed by blending the heat fusible fiber. It is presumed that the smoothness was improved and the coloring of the ink was improved.

On the other hand, in Comparative Example 1 using continuous filaments and Comparative Example 4 using fibers having a fiber length to fiber diameter ratio of less than 800, the sheet was torn by outdoor wind and rain, making it difficult to use it outdoors. It is. The ratio of fiber length to fiber diameter is 10,000
In Comparative Example 5 using fibers exceeding the number of fibers, lumps generated by entanglement of the fibers occur frequently in the sheet, and the sheet becomes unsightly in appearance. In Comparative Example 2 using a fiber having a fiber diameter of less than 0.3 μm, water resistance was difficult, and the image density was reduced when used outdoors, so that it could not be used. In Comparative Example 3 using a fiber having a fiber diameter of more than 20 μm, color development of an image is poor.

[0060]

The ink jet recording sheet according to the first aspect of the present invention is a non-woven fabric mainly composed of fibers having a fiber diameter of 0.3 μm to 20 μm and a fiber length divided by a fiber diameter of 800 to 10,000. By using as a support, it is possible to obtain an ink jet recording sheet having a unique cloth-like texture, good color development of a recorded image, and a high sheet strength that can withstand outdoor use.
The ink-jet recording sheet of the second aspect of the present invention has, as a support, a fiber having a fiber diameter of 0.3 μm or more and 20 μm or less, and a value obtained by dividing the fiber length by the fiber diameter of 100 parts or more of the main fibers having a fiber length of 800 or more and 10,000 or less. On the other hand, 1
By using a nonwoven fabric in which the amount is not less than 50 parts by weight, in addition to the above characteristics, the surface of the ink receiving layer becomes smooth, and it is possible to obtain an ink jet recording sheet having more favorable coloring of a recorded image. Further, in the above two inventions, by containing a synthetic amorphous silica having an average particle diameter of 2 μm or more and 10 μm or less as a white pigment in the ink receiving layer, in addition to the above characteristics, the discoloration of a recorded image when left outdoors is reduced. It is possible to provide an ink jet recording sheet that hardly occurs and exhibits good image storability.

Claims (3)

[Claims] 1. An ink jet recording sheet having an ink receiving layer provided on one surface of a support, wherein the support has a fiber diameter of 0.3 μm to 20 μm, and a fiber length divided by a fiber diameter. Is a non-woven fabric mainly composed of fibers of 800 or more and 10,000 or less. 2. In an ink jet recording sheet having an ink receiving layer provided on one surface of a support, the support has a fiber diameter of 0.3 μm or more and 20 μm or less, and the fiber length is divided by the fiber diameter. An ink jet recording sheet comprising a fiber having a value of 800 or more and 10,000 or less as a main fiber, and a nonwoven fabric containing 1 to 50 parts of a heat-fused fiber with respect to 100 parts of the main fiber. 3. The ink jet recording sheet according to claim 1, wherein the ink receiving layer contains a synthetic amorphous silica having an average particle size of 2 μm to 10 μm as a white pigment.